There's been at least 3 Hall Brawls if not more.
Every time they do it, there is usually a big mismatch in weight and size. It can't be an accident. The producers seem to deliberately go for the Hall Brawl whenever there's a bigger vs. smaller matchup or the chance of it.
For all we know, they could have winked at Fessy and that is why he volunteered.
In this case, Fessy would have a big advantage against any guy. He's the size of an NFL TE, used to firing out and leading with the helmet and shoulder pads to hit people, only in football games, he's going against guys closer to his size and strength.
Maybe logistics limited the number of types of eliminations they could have. But I think a more likely reason is they like Fessy for whatever reason. They've given him a lot of air time this season and maybe his cockiness and villainy makes the producers think he could be the next Bananas.
Whatever the case, there is no transparency at all whatsoever and they don't pretend to be trying to create fair competition.
A long time ago, they used to have a spinning wheel so the type of elimination wouldn't be determined by producers off screen. In fact, they're not even pretending that the type of elimination was chosen randomly. They don't say for instance "we had a drawing in the office and this one came up again!"
For one thing, the Double Agents wouldn't be able to decide whether to go compete themselves or send someone else because they couldn't tell what the elimination would be until they spun the wheel.
As for the political shenanigans, Leroy and Cam better win this because either way they were betraying someone so other challengers would be wary of forming an alliance with them in the future. Supposedly Leroy is done after this one. But if Cam comes back, people might remember what she did to Kyle and what she would have done to Cory.
However, these guys know whom they're friendly with. They probably calculated that Cory would have more friends or bigger alliances in future seasons than Kyle would. Could also be that they think Cory would run the Final more competitively as Cam's partner, though I don't know how he fares in distance.
As for the other teams, I think Kaycee and Amber may actually be in better condition to do an endurance challenge than Cam or Nany.
Of course Amber can't do math. She's all weepy about being disrespected. Well, you couldn't do a math equation that a second grader could solve, honey.